Combinatorial plasma enhanced deposition techniques

ABSTRACT

Combinatorial plasma enhanced deposition techniques are described, including designating multiple regions of a substrate, providing a precursor to at least a first region of the multiple regions, and providing a plasma to the first region to deposit a first material on the first region formed using the first precursor, wherein the first material is different from a second material formed on a second region of the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 12/433,842 titled “Combinatorial Plasma EnhancedDeposition Techniques,” and filed on Apr. 30, 2009, with a Notice ofAllowance on Nov. 16, 2011, which claims the benefit of U.S. ProvisionalApplication No. 61/050,159 titled “Combinatorial Plasma EnhancedDeposition Techniques,” and filed on May 2, 2008, and to U.S. Utilityapplication Ser. No. 12/433,842 titled “Combinatorial Plasma EnhancedDeposition Techniques,” and filed on Apr. 30, 2009, each of which isincorporated herein by reference.

This application is related to U.S. patent application Ser. No.12/013,729 entitled “Vapor Based Combinatorial Processing” and filedJan. 14, 2008, which is herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to semiconductor processing.More specifically, techniques for combinatorial plasma enhanceddeposition techniques are described.

BACKGROUND OF THE INVENTION

Chemical vapor deposition (CVD) is a process used to deposit thin filmsfor semiconductor fabrication. CVD typically includes introducing one ormore reagents (e.g., precursors) to a substrate in a processing chamber.The reagents react and/or decompose to deposit the films. Longer CVDprocessing times (i.e., longer exposure to reagents) typically increaselayer thickness. Plasma enhanced CVD (PECVD) uses plasma in theprocessing chamber to increase the reaction rates of the reagents andcan allow deposition at lower temperatures. Plasma species can also beused to modify the resulting film properties.

Atomic layer deposition (ALD) is a process used to deposit conformallayers with atomic scale thickness control during various semiconductorprocessing operations. ALD may be used to deposit barrier layers,adhesion layers, seed layers, dielectric layers, conductive layers, etc.ALD is a multi-step self-limiting process that includes the use of atleast two reagents. Generally, a first reagent (which may be referred toas a precursor) is introduced into a processing chamber containing asubstrate and adsorbs on the surface of the substrate. Excess of theprecursor is purged and/or pumped away. A second reagent (e.g., watervapor, ozone, or plasma) is then introduced into the chamber and reactswith the adsorbed layer to form a deposited layer via a depositionreaction. The deposition reaction is self-limiting in that the reactionterminates once the initially adsorbed layer is fully reacted with thesecond reagent. Excess second reagent is then purged and/or pumped away.The aforementioned steps constitute one deposition or ALD “cycle.” Theprocess is repeated to form the next layer, with the number of cyclesdetermining the total deposited film thickness. Plasma enhanced ALD(PEALD) is a variant of ALD that uses plasma as the second reagent,where plasma constitutes a quasi-static equilibrium of ions, radicalsand neutrals derived from the constituent feed gases.

CVD and ALD can be performed using a processing chamber that includes ashowerhead above a substrate. The reagents are introduced to thesubstrate through the showerhead. For plasma enhanced processes, plasmacan be generated using a radio frequency (RF) or direct current (DC)discharge between two electrodes in the chamber. The discharge is usedto ignite reacting gasses in the chamber.

Semiconductor research and development is typically performed by usingproduction tools. Therefore, to explore new CVD and ALD techniques or toevaluate materials deposited using CVD or ALD, a layer must be depositedover an entire wafer. The process of investigating semiconductorprocesses and materials in this way can be slow and expensive.

Thus, what is needed are improvements in semiconductor development usingcombinatorial plasma enhanced deposition techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are disclosed in the followingdetailed description and the accompanying drawings:

FIG. 1A illustrates a substrate having multiple regions;

FIG. 1B is a schematic diagram illustrating an implementation ofcombinatorial processing and evaluation;

FIGS. 2A-2E illustrate a substrate processing system and componentsthereof in accordance with one embodiment of the present invention;

FIG. 3 is a simplified diagram showing a processing system capable ofdepositing different materials in multiple regions under varyingconditions using plasma-enhanced CVD (PECVD) or plasma-enhanced ALD(PEALD);

FIG. 4A is a view of the underside of a showerhead for a depositionsystem;

FIG. 4B illustrates a substrate having multiple regions with differentmaterials deposited thereon;

FIG. 5 illustrates a combinatorial processing system including analternative showerhead for performing combinatorial material deposition;

FIG. 6 is an electrical equivalence circuit showing the ignition ofplasma in one region of a substrate and not in others;

FIG. 7 is a flowchart describing a process for varying plasma acrossmultiple regions of a substrate to process the substratecombinatorially; and

FIGS. 8-11 are timing diagrams for performing combinatorial plasmaenhanced ALD processing.

DETAILED DESCRIPTION

A detailed description of one or more embodiments is provided belowalong with accompanying figures. The detailed description is provided inconnection with such embodiments, but is not limited to any particularexample. The scope is limited only by the claims and numerousalternatives, modifications, and equivalents are encompassed. Numerousspecific details are set forth in the following description in order toprovide a thorough understanding. These details are provided for thepurpose of example and the described techniques may be practicedaccording to the claims without some or all of these specific details.For the purpose of clarity, technical material that is known in thetechnical fields related to the embodiments has not been described indetail to avoid unnecessarily obscuring the description.

According to various embodiments, parameters or conditions for plasmaenhanced chemical vapor deposition (PECVD) and plasma enhanced atomiclayer deposition (PEALD) can be varied combinatorially across regions ofa substrate. The combinatorial variation can be used to explore newmaterials using plasma enhanced techniques or to determine optimalprocess parameters or conditions for performing plasma enhancedtechniques. In some embodiments, plasma can be used as a reagent orenhancement over the entire substrate while other parameters (e.g.,types of precursors, exposure time) are varied across regions of thesubstrate. In other embodiments, the types of plasma or existence ofplasma can be varied across regions. For example, two regions of asubstrate can be exposed to plasma, while two regions of the substrateare exposed to either no enhancements or other reagents. The resultingmaterials can then be characterized and evaluated to determine anoptimal process solution. Techniques and devices for differentiallyproviding plasma regions of a substrate are described below.

Plasma can be created in a processing chamber by providing a plasma gasbetween two electrodes and generating a voltage difference between thetwo electrodes. The power required to ionize the feed gases is derivedfrom either capacitively coupled or inductively coupled sources. Plasmarefers to a quasi-static equilibrium of ions, radicals and neutrals thatresult from certain conditions when the gases are at the optimumpressure in the presence of the applied potential. Some gasses areeasier to breakdown and hence ignite (i.e., it is easier to create aplasma) than others. Additionally, the distance between the twoelectrodes can influence whether or not a plasma is struck. According tovarious embodiments described below, the composition of plasma gasses,the chamber pressure and the distance between electrodes can be variedto perform plasma enhanced deposition combinatorially. Other embodimentsprovide combinatorial plasma using remote sources of plasma.

I. Combinatorial Processing

“Combinatorial Processing” generally refers to techniques ofdifferentially processing multiple regions of a substrate. Combinatorialprocessing can be used to produce and evaluate different materials,chemicals, processes, and techniques related to semiconductorfabrication as well as build structures or determine how the above coat,fill or interact with existing structures. Combinatorial processingvaries materials, unit processes and/or process sequences acrossmultiple regions on a substrate.

A. Multiple Regions on a Substrate

FIG. 1A illustrates a substrate 100 having multiple regions. Thesubstrate 100 includes multiple wedge-shaped regions 102. The wedgeshaped-regions 102 can be formed using techniques such CVD, ALD, PECVD,and PEALD. For example, a different material can be deposited in each ofthe regions 102 by varying the precursors, reagents, exposure time,temperature, pressure, or other processing parameters or conditions. Theregions 102 can then be examined and compared to determine which of thematerials or techniques merits further study or is useful forproduction. Although, as shown here, the substrate 100 is divided intofour wedges, it is understood that any number of regions having anyshape may be used. Additionally, the substrate 100 is a circular wafer,however any shape or size of substrate may be used, includingrectangular coupons that are diced from larger wafers. The substrates orwafers may be those used in integrated circuits, semiconductor devices,flat panel displays, optoelectronic devices, data storage devices,magnetoelectronic devices, magnetooptic devices, molecular electronicdevices, solar cells, photonic devices, packaged devices, and the like.

As an example, two precursors can be used to deposit two differentmaterials on the substrate 100. A first precursor A can be used todeposit, for example, aluminum in regions 102 a and 102 b, and a secondprecursor B can be used to deposit, for example, hafnium in regions 102c and 102 d. The precursor A can have a different exposure time, flowrate, etc. in region 102 a than in region 102 b. Additionally, one ormore of the regions may use plasma as an enhancement or a reagent. Thedescription below includes embodiments for providing a plasma to aportion of a substrate.

A unit process is an individual process used for semiconductorfabrication. Examples of unit processes for CVD and ALD processinginclude introducing a reagent or precursor, purging, and applying apotential between two electrodes. A process sequence is the sequence ofindividual unit processes used to perform a semiconductor process (e.g.,to deposit a layer).

Using combinatorial processing, any of the materials, unit processes, orprocess sequences can be varied across regions of one or moresubstrates. As examples:

-   -   Different materials (or the same material having different        characteristics) can be deposited on different regions of one or        more substrates.    -   Different unit processes can be performed across regions, or        variations of unit processes (e.g., expose a precursor for 10        seconds on one region and 10 seconds on another) can be        performed.    -   The order of unit processes, e.g., the sequence of individual        unit processes used to deposit one or more layers can be        changed. Additionally, unit processes can be added to or omitted        from process sequences.        B. Combinatorial Evaluation

FIG. 1B is a schematic diagram 140 illustrating an implementation ofcombinatorial processing and evaluation. The schematic diagram 140illustrates that the relative number of combinatorial processes run witha group of substrates decreases as certain materials and/or processesare selected. Generally, combinatorial processing includes performing alarge number of processes and materials choices during a first screen,selecting promising candidates from those processes, performing theselected processing during a second screen, selecting promisingcandidates from the second screen, and so on. In addition, feedback fromlater stages to earlier stages can be used to refine the successcriteria and provide better screening results.

For example, thousands of materials are evaluated during a materialsdiscovery stage 142. Materials discovery stage 142 is also known as aprimary screening stage performed using primary screening techniques.Primary screening techniques may include dividing wafers into regionsand depositing materials using varied processes. The materials are thenevaluated, and promising candidates are advanced to the secondaryscreen, or materials and process development stage 144. Evaluation ofthe materials is performed using metrology tools such as physical andelectronic testers and imaging tools.

The materials and process development stage 144 may evaluate hundreds ofmaterials (i.e., a magnitude smaller than the primary stage) and mayfocus on the processes used to deposit or develop those materials.Promising materials and processes are again selected, and advanced tothe tertiary screen or process integration stage 146, where tens ofmaterials and/or processes and combinations are evaluated. The tertiaryscreen or process integration stage 146 may focus on integrating theselected processes and materials with other processes and materials intostructures.

The most promising materials and processes from the tertiary screen areadvanced to device qualification 148. In device qualification, thematerials and processes selected are evaluated for high volumemanufacturing, which normally is conducted on full wafers withinproduction tools, but need not be conducted in such a manner. Theresults are evaluated to determine the efficacy of the selectedmaterials, processes, and integration. If successful, the use of thescreened materials and processes can proceed to manufacturing 150.

The schematic diagram 140 is an example of various techniques that maybe used to evaluate and select materials, processes, and integration forthe development of semiconductor devices. The descriptions of primary,secondary, etc. screening and the various stages 142-150 are arbitraryand the stages may overlap, occur out of sequence, be described and beperformed in many other ways.

II. Combinatorial CVD/ALD Processing System

FIGS. 2A-2E illustrate a substrate processing system 200 and componentsthereof in accordance with one embodiment of the present invention. Thesubstrate processing system 200 includes an enclosure assembly 202formed from a process-compatible material, for example aluminum oranodized aluminum. Enclosure assembly 202 includes a housing 204defining a processing chamber 206 and a vacuum lid assembly 208 coveringan opening to processing chamber 206. A wafer transfer channel 210 ispositioned in housing 204 to facilitate transfer of a substrate,discussed more fully below, between processing chamber 206 and anexterior thereto. Mounted to vacuum lid assembly 208 is a process fluidinjection assembly that delivers reactive and carrier fluids intoprocessing chamber 206, discussed more fully below. To that end, thefluid injection assembly includes a plurality of passageways 212 a, 212b, 212 c and 212 d and a showerhead 214. The chamber housing 204, vacuumlid assembly 208, and showerhead 214 may be maintained within desiredtemperature ranges in a conventional manner Various embodiments of theshowerhead 214 are discussed below (see e.g., FIGS. 2C-2E and 4A).

A heater/lift assembly 216 is disposed within processing chamber 206.Heater/lift assembly 216 includes a support pedestal 218 connected to asupport shaft 220. Support pedestal 218 is positioned between shaft 220and vacuum lid assembly 208, when vacuum lid assembly 208 is in a closedposition. Support pedestal 218 may be formed from any process-compatiblematerial, for example aluminum nitride and aluminum oxide (Al₂O₃ oralumina) and is configured to hold a substrate thereon, e.g., supportpedestal 218 may be a vacuum chuck or utilize other conventionaltechniques such as an electrostatic chuck (ESC) or physical clampingmechanisms. Heater lift assembly 216 is adapted to be controllably movedso as to vary the distance between support pedestal 218 and theshowerhead 214 to control the substrate to showerhead spacing. Asdescribed herein, the distance between the showerhead 214 and thepedestal 218 can be varied to enable or disable the ignition of a plasmaacross regions of a substrate. A sensor (not shown) provides informationconcerning the position of support pedestal 218 within processingchamber 206. Support pedestal 218 can be used to heat the substratethrough the use of heating elements (not shown) such as resistiveheating elements embedded in the pedestal assembly.

Referring to both FIGS. 2A and 2B a fluid supply system 222 is in fluidcommunication with passageways 212 a, 212 b, 212 c and 212 d through asequence of conduits. Flows of processing fluids, from fluid supplysystem 222, within processing chamber 206 are provided, in part, by apressure control system that may include one or more pumps, such asturbo pump 224 and roughing pump 226 both of which are in fluidcommunication with processing chamber 206 via a butterfly valve 228 andpump channel 230. To that end, a controller 232 regulates the operationsof the various components of system 200. Controller 232 includes aprocessor 234 in data communication with memory, such as random accessmemory 236 and a hard disk drive 238 and is in signal communication withturbo pump 224, temperature control system 240, fluid supply system 222and various other aspects of the system as required. System 200 mayestablish conditions in a processing region 242 of processing chamber206 located proximate to a surface 244 of a substrate 246 disposed onsupport pedestal 218 to form desired material thereon, such as a thinfilm. To that end, housing 204 is configured to create a peripheral flowchannel 248 that surrounds support pedestal 218 when placed in aprocessing position to provide processing region 242 with the desireddimensions based upon chemical processes to be achieved by system 200.Pump channel 230 is situated in housing 204 so that processing region242 is positioned between pump channel 230 and showerhead 214.

The dimensions of peripheral flow channel 248 are defined to provide adesired conductance of processing fluids therethrough which provideflows of processing fluids over a surface of substrate 246 in asubstantially uniform manner and in an axisymmetric fashion as furtherdescribed below. To this end, the conductance through pump channel 230is chosen to be larger than the conductance through peripheral flowchannel 248. In one embodiment, the relative conductance of processingfluids through pump channel 230 and peripheral flow channel 248 is, forexample, 10:1, wherein the conductance of pump channel 230 isestablished to be at least ten (10) times greater than the conductanceof processing fluids through peripheral flow channel 248. Such a largedisparity in the conductance, which may be other ratios, serves tofacilitate axisymmetric flow across the surface of substrate 246 asshown by flows A and B moving through processing region 242 andsubsequently passing substrate 246 and support pedestal 218 toward pumpchannel 230.

To provide plasma to the substrate 246, a voltage difference can becreated between the showerhead 214 and the pedestal 218 while a plasmagas is supplied to the processing region 242. To this end, the potentialcan be created by: 1) connecting the showerhead 214 to a power sourcesuch as a radio frequency (RF) power source and the pedestal 218 toground; 2) connecting the showerhead 214 to ground and the pedestal 218to a power source such as an RF power source; or 3) connecting both theshowerhead 214 and the pedestal 218 to power sources (e.g., RF) havingdifferent phases. It is to be appreciated that any other technique forcreating a potential difference between the showerhead 214 and thepedestal 218 can also be used. For example, instead of using an RF powersource, a direct current (DC) power source can also be used. A plasmagas is the gas that will be ignited by the voltage difference. Forexample, the plasma gas could be argon, hydrogen, oxygen, nitrogen, orany combination thereof. As will be described below, multiple plasmagasses can be used so that a plasma ignites over some regions of thesubstrate and not others.

Referring to FIGS. 2B-2D, to facilitate the occurrence of flows A and B,showerhead 214 includes a baffle plate 252 that is formed to be radiallysymmetric about a central axis 254, but need not be. Baffle plate 252has first and second opposed surfaces 256 a and 256 b, with a pluralityof through ports 258 a, 258 b, 258 c and 258 d extending therebetween.Coupled to baffle plate 252 is a manifold portion 260 having a pluralityof injection ports 262 extending through manifold portion 260. Manifoldportion 260 is typically disposed to be radially symmetric about axis254. Manifold portion 260 is spaced-apart from surface 256 b to define aplenum chamber 264 therebetween. Manifold portion 260 may be coupled tobaffle plate 252 using any means known in the semiconductor processingart, including fasteners, welding and the like. Baffle plate 252 andshower head 214 may be formed from any known material suitable for theapplication, including stainless steel, aluminum, anodized aluminum,nickel, ceramics and the like.

Referring to FIGS. 2B-2D, extending from manifold portion 260 is a fluidseparation mechanism that includes a body 266 extending from manifoldportion 260 toward baffle plate 252. The distance that body extends fromsurface is dependent upon the specific design parameters and may extendto cover part of the distance or the entire distance to create segmentswithin the plenum 264, as discussed more fully below. In one embodiment,body 266 may extend between the manifold 260 and baffle 252 in twoorthogonal directions to create four regions, referred to as quadrantsor segments 268 a, 268 b, 268 c and 268 d. Although four quadrants areshown, any number of segments may be provided by adding additional bodyportions 266 or modifying the port location and/or showerhead outletpattern, depending upon the number of regions one wants to or can defineon substrate 246. A vertex 270 of body 266 is generally aligned withaxis 254. Passageways 212 a-212 d are configured to direct fluid throughfour ports shown as 258 a-258 d. In this manner, ports 258 a-258 d arearranged to create flows of processing fluids that are associated with acorresponding one of quadrants 268 a-268 d. The body 266 providessufficient separation to minimize, if not prevent, fluids exiting ports258 a-258 d from diffusing between adjacent quadrants 268 a-268 d. Inthis manner, each of the four ports 258 a-258 d directs a flow ofprocessing fluids onto one of quadrants 268 a-268 d that differs fromthe quadrants 268 a-268 d into which the remaining ports 258 a-258 ddirect flows of processing fluids.

FIG. 2E illustrates optional protrusions extending from the underside ofthe showerhead 214. The protrusions 272 are used to isolate the regionsof the substrate. Protrusions 272 can be arranged such that there is aprotrusion to isolate each region of the substrate. For example, asshown in FIG. 2E, four protrusions 272 are used to isolate orsubstantially isolate four regions on the substrate 246. The protrusions272 may substantially prevent gasses such as reagents from migratingfrom the region in which they are intended to be introduced to anadjoining region. Additionally the protrusions 272 also prevent a plasmagenerated in one region from spreading and igniting gases in the otherregion The protrusions 272 can be in contact with the substrate 246 orsome distance from the surface 244 of the substrate (e.g., 0.5-5 mm) Thespacing between the protrusions and the wafer become important inensuring a dark space where plasma cannot sustain itself.

III. Combinatorial PEVCD/PEALD Processing System

A. Segmented Showerhead for Combinatorial PECVD/PEALD

FIG. 3 is a simplified diagram showing a processing system 300 capableof depositing different materials under varying conditions usingplasma-enhanced CVD (PECVD) or plasma-enhanced ALD (PEALD). FIG. 4A is aview of the underside of the showerhead 214. FIG. 4B illustrates thesubstrate 246 having multiple regions 402 with different materials 302deposited thereon.

Using the processing system 300, plasma can be selectively applied toregions of the substrate 246 such that different materials (e.g.,materials 302 a-302 d) are formed on different regions 402 a-402 d ofthe substrate 246. The materials 302 a-302 d can be considered differentif they are formed using varying processing parameters. For example,different precursors can be used in different regions, the sameprecursors can be used but with and without plasma in some regions, orsome combination of parameters (e.g., RF power, duration, etc.). Theregions 402 and the segments 268 of the showerhead 214 may have anysize, shape, or configuration, but according to one embodiment, theregions 402 have a common size and shape. According to variousembodiments, parameters or conditions of PECVD and PEALD that can bevaried for combinatorial processing include power to ignite plasma, flowof plasma and other gasses, the type of plasma gas, pressure, selectionof precursors, exposure time, spacing, etc.

Plasma can also be used to pre-treat a substrate prior to an ALD or CVDprocess. Plasma can be used, for example, to remove contamination suchas unwanted oxidation on the surface of a substrate. For example, if acopper substrate has surface oxides, the plasma can be applied to removethe unwanted oxides. Other plasma pre-treatments, such as to improvewettability of the substrate, can also be used. The plasma can beapplied either to the entire substrate or combinatorially to someregions and not to others. Either parameters of the plasma (e.g., plasmagas composition) or the use of plasma versus not using plasma can bevaried across regions of a substrate and evaluated in a combinatorialprocess. In some embodiments, combinatorial plasma pre-treatment can beused with subsequent non-combinatorial ALD or CVD processes (i.e., usingthe same processing conditions across the entire substrate).

Additionally, the entire substrate 246 may have plasma applied to it,but using different precursors or other processing conditions acrossdifferent regions so that different materials are deposited. As usedherein, a material (e.g., comprising a thin film or layer) is differentfrom another material if the materials have different compositions,grain structures, morphologies, thicknesses, etc. In one embodiment, thefluid flow into the chamber 206 is approximately constant amount of flowacross each region (e.g., 250 sccm). The timing diagrams of FIGS. 8-11explain the total fluid flow in more detail.

Using plasma or other reagents during the second half of an ALD cycle orusing plasma to enhance CVD processes can be a combinatorial variableaccording to various embodiments. Various techniques can be used toprovide isolated plasma within the chamber 206. According to embodimentsdescribed herein, plasma can be provided to individual regions (and notto others) of the substrate 246 either in situ or ex situ:

Ex situ application of plasma can be performed using a remote plasmasource 304 that generates ions, atoms, radicals and other plasmaspecies. The plasma species from the remote plasma source 304 areprovided to the substrate 246 using the fluid supply system 222. Theremote plasma source 304 receives a feed gas 314 (i.e., a plasma gas)such as oxygen, hydrogen, ammonia, or argon and generates plasma speciessuch as radicals, ions, atoms, etc. The remote plasma source 304 can beany type of plasma source such as a radiofrequency, microwave, orelectron cyclotron resonance (ECR) upstream plasma source.

The fluid supply system 222 can deliver fluids from multiple sources.For example, one or more ALD or CVD precursors 306 can be simultaneouslyor sequentially provided to regions 402 the substrate 246. When using aplasma enhanced ALD system, the precursor and the plasma are bothreagents that are reacted to form layers on the substrate 246. Ex situplasma can be differentially applied by flowing plasma species to someof the regions 402 and not to others or by using different plasmacharacteristics or parameters for different regions 402.

In situ plasma can be provided by creating a voltage difference betweentwo electrodes (e.g., the showerhead 214 and the pedestal 218). In situplasma can be differentially applied by flowing different gasses todifferent regions 402 of the substrate 246. Paschen's Law dictates theconditions under which a plasma is formed through a gas. According toPaschen's law, for a given gas between two electrodes, a plasma isformed when a voltage difference greater than or equal to a breakdownvoltage (V_(B)) is applied between the two electrodes (e.g., theshowerhead 214 and the pedestal 218). V_(B) is dependent on the distancebetween the electrodes (e.g., the distance d 308) and the pressure ofthe gas inside the chamber:V _(B) =f(pd)  Equation 1where f is an intrinsic property of the gas present in the chamber.Accordingly, for constant distance between the electrodes and a constantpressure in the chamber 206, the ignition of a plasma when a voltagedifference is applied depends on an intrinsic property of the plasmagas. According to an embodiment of the invention, one segment 268 of theshowerhead 214 can provide a gas that ignites easily (e.g., Ar), whileanother segment 268 provides a gas that is difficult to ignite (e.g.,H₂). Other plasma gasses that can be used include oxygen, nitrogen,ammonia, etc. In this way, plasma can be provided to one region 402 ofthe substrate 246, while it is not provided to another region 402. As aresult, different materials can be formed in the multiple regions 402 ofthe substrate 246 in a combinatorial manner by varying the plasma. Forexample, plasma can be used as a reagent in one region 402 a ofsubstrate 246 while another reagent is used in a second region 402 b ofthe substrate 246. Examples of doing so are described below regardingthe timing diagrams in FIGS. 8-11. Other techniques for providing plasmato some regions of the substrate 246 and not others are described below.

A voltage difference between the showerhead 214 and the pedestal 218 canbe provided in several ways. According to one embodiment, aradiofrequency (RF) power source 310 is attached to one or both of theshowerhead 214 and the pedestal 218. The RF power source can use anyfrequency including 2 megahertz (MHz), 3.39 MHz, 13.56 MHz, 60 MHz,300-500 kilohertz (kHz) and other frequencies. In one embodiment, theshowerhead 214 is powered using the power source 310 a and the pedestal218 is attached to a ground 312 a. In a second embodiment, the pedestal218 is attached to the power source 310 b and the showerhead is attachedto a ground 312 b. In a third embodiment, both the showerhead 214 andthe pedestal 218 are attached to the RF power sources 310 a and 310 b,respectively. With the third embodiment, the power sources 310 a and 310b can be offset in either or both of frequency or phase. Any of theseembodiments can provide the voltage differences between the showerhead214 and the pedestal 218 to ignite or not ignite a plasma in the chamber206 as desired. Other types of power sources, such as direct current(DC) power sources, can also be used to generate the voltage difference.According to one embodiment, to avoid damage to preformed devices on asubstrate, the power supplied is less than 1.0 W/cm². However, it isunderstood that any amount of power can be used.

FIG. 4A is an underside view of the showerhead 214. The segments 268 andinjection ports 262, as well as the protrusions 272 are visible. FIG. 4Bis an overhead view of the substrate 246 having different materialscombinatorially deposited thereon. The segments 268, in this embodiment,correspond to the regions 402 of the substrate 246. Therefore,precursors to form the materials 302 are emitted by the correspondingsegments 268 of the showerhead 214.

“Dark” regions 404 are the areas between the regions 402 of thesubstrate 246. The dark regions 404 are in between the exposed regions402 and exposure to reagents in the dark regions 404 is primarily theresult of reagent migration from the exposed regions 402. These darkregions 404 can be minimized or eliminated in some embodiments by usingprotrusions 272 or by adjusting the flow conditions in the chamber,flow, port location and/or showerhead configurations, and other possibletechniques.

When a precursor or a gas is introduced by gas injection system 222, thechemical reagents interact on the substrate 246 to form the materials302. The substrate 246 has different materials 302 deposited on fourdifferent regions 402. As described above, materials can be considereddifferent if they vary in any substantive way, such as in composition(i.e., chemical constituents), morphology, thickness, etc. For example,each of the materials 302 could be deposited using different precursors.The material 302 a could be tantalum (formed using a tantalum precursorsuch as tris(diethylamino)(tert-butylimido) tantalum (TBTDET)), thematerial 302 b could be titanium (formed using a titanium precursor suchas tetrakis diethylamido titanium (TDEAT)), the material 302 c could behafnium (formed using a hafnium precursor such as tetrakis(dimethylamido) hafnium (TDMAHf)), and the material 302 d could beruthenium (formed using a ruthenium precursor such asbis(methylcyclopentadienyl)ruthenium(Ru(MeCp)₂)). In this manner, fourdifferent materials are combinatorially deposited using four differentprecursors. Alternatively, processing sequences or other processingconditions can be varied by region or across regions to create acombinatorial array. The specific variation is generally defined in thedesign of experiment, but need not be so defined.

According to an embodiment, one process parameter that can be variedacross regions is the presence or absence of plasma in a region of thesubstrate. For example, a plasma could be ignited in the region 402 a,but not in the regions 402 b-402 d. The plasma could be a reagent usedwith a PEALD or PECVD process. Other reagents (e.g., water vapor) can beused for the other regions in which no plasma is struck. As describedabove, the ignition of a plasma depends on the distance between theelectrodes (e.g., the showerhead 214 and the pedestal 218), the pressurein the chamber 206, and the gas used for the plasma. Embodiments of theinvention describe varying the distance and gas composition todifferentially provide plasma across a substrate.

B. Alternative Showerhead for Combinatorial PECVD/PEALD

FIG. 5 illustrates a combinatorial processing system 500 including analternative showerhead 214 for performing combinatorial materialdeposition. As discussed above, the ignition of a plasma (i.e., thebreakdown voltage) depends on the distance between the electrodes (e.g.,the showerhead 214 and the pedestal 218). The alternative showerhead 214shown includes segments 268 a and 268 b having different distances(e.g., the distances d₁ 502 a and d₂ 502 b) from the pedestal 218. Asingle plasma gas can be fed into the chamber, and the plasma gas andthe position of the pedestal can be chosen so that the distance 502 a istoo large to ignite a plasma, while the distance 502 b is sufficient toignite a plasma or vice versa (e.g., the distance 502 a ignites a plasmaand the distance 502 b is too small to ignite a plasma). In this way, aplasma can be ignited in some regions, and not in others.

According to another embodiment, the segments 268 can be dynamicallymovable relative to the substrate 246. For example, the distances d₁ 502a and d₂ 502 b can be dynamically adjusted according to the requirementsof a particular combinatorial experiment. Additionally, the showerhead214 (including the alternative showerhead shown here) can be moved as aunit relative to the substrate 246 to change the distances d₁ 502 a andd₂ 502 b. Further, either or both of the showerhead 214 or the pedestal218 can be rotatable to alter the distance between the showerhead 214and a region 404 of the substrate 246 when using the alternativeshowerhead 214 shown here.

C. Moving Plasma Between Regions

A plasma can be ignited in one region 402 of a substrate 246 andsubsequently moved to another region 402 to effect combinatorialprocessing. Two techniques for moving a plasma from one region toanother region are described.

1. Changing Gas Mixture

A first technique uses the showerhead 214 shown in FIGS. 2C-2E and 3.The showerhead 214 creates a plasma in a first region, e.g., the region402 a, by providing a plasma gas (e.g., Ar) and a voltage differencebetween the showerhead 214 and the pedestal 218, while using a gas thatdoes not ignite in the other regions 402 of the substrate 246. At alater time, the voltage difference is maintained, but the plasma gas inthe first region is changed to one that does not ignite under thecircumstances (e.g., a purge gas), and a plasma gas (e.g., Ar) that doesignite under the circumstances is then fed into a second region (e.g.,the region 402 b). The removal of the ignitable plasma gas from thefirst region and introduction of an ignitable gas into the second regiontransfers the plasma from the first region to the second region.According to an embodiment, there may be a period of overlap where thereis a plasma in both regions. According to further embodiments, anynumber of regions may have a plasma at any time, and the regions may ormay not be adjacent.

2. Rotating Pedestal

According to one embodiment, the pedestal 218 can be rotatable. A plasmacan be struck in one region (e.g., the region 402 a) by providing anappropriate plasma gas through a segment (e.g., the segment 268 a) ofthe showerhead 214 corresponding to the region. The substrate 246 can berotated to transfer the plasma to another region (e.g., the region 402b).

This embodiment can also be used with the alternative showerhead 214shown in FIG. 5. For example, with the alternative showerhead 214 shownin FIG. 5, the region 402 a can be exposed to a precursor emitted by thesegment 268 a and the region 402 b can be exposed to a precursor emittedby the segment 268 b. In this example, the segment 268 b is closer tothe pedestal 218 and a plasma ignites in the region 402 b, but not inthe region 402 a. The pedestal 218 can be rotated to transfer the plasmato the region 402 a by moving the region 402 a underneath the segment268 b.

Additionally, the rotation of the pedestal 218 can be used to createadditional regions. For example, if the showerhead 214 is divided intofour segments 268, more than four different materials 302 can be createdon the substrate 246 by rotating the pedestal 218. The pedestal can berotated by ½ a region (i.e., 45°) in this example to create eightregions. Four precursors can be emitted by the four segments 268. Duringthe emission of those precursors, the pedestal 218 can be rotated by 45°to create an additional four regions by exposing half of each region toanother precursor. For example, precursor A is emitted by segment 268 aonto region 402 a, and precursor B is emitted by segment 268 b ontoregion 402 b. During the exposure of the precursors, the pedestal isrotated so that half of region 402 a is now exposed to precursor B,while the remainder of region 402 a continues to be exposed to precursorA. The resulting eight regions include four regions exposed to a singleprecursor and four regions that are exposed to a mixture of precursors.It is understood that any number of regions combined with any amount ofrotation and exposure to precursors can be used to create any number ofregions.

D. Electrical Equivalence Circuit

FIG. 6 is an electrical equivalence circuit 600 showing the ignition ofplasma in one region of a substrate and not in others. The equivalencecircuit 600 shows the flow of current through segments 268 and regions402 of the substrate. For example, open switches 602, 604, and 608indicate that there is no plasma in the regions 402 a, 402 b, and 402 d,respectively. The closed switch 606 indicates a flowing current and theexistence of plasma in the region 402 c. The ignition of a plasma in aregion effectively completes a circuit between the two electrodes (i.e.,the showerhead 214 and the pedestal 218) in that region. In thisexample, the region 402 c represented by the closed switch 606 has aplasma gas that ignites more easily than the plasma gasses in the otherregions. In another example as described regarding FIG. 5, the distancebetween the showerhead 214 and the pedestal 218 in the region 402 c maybe different than the distance between the showerhead 214 and thepedestal 218 in other regions.

IV. Process for Performing Combinatorial Evaluation Using PECVD or PEALD

FIG. 7 is a flowchart describing a process 700 for varying plasma acrossmultiple regions of a substrate to process the substratecombinatorially. The process 700 described in FIG. 7 is one embodimentof forming a material or analyzing deposition parameters (e.g.,precursors, temperatures, existence of plasma) in a combinatorialfashion using PECVD or PEALD.

In operation 702, multiple regions of a substrate are designated. Insome embodiments, designating the regions includes determining theapproximate location and boundaries of regions of a substrate. Forexample, as shown in FIG. 4B, several regions 402 are designated on thesubstrate 246. The regions can, in some embodiments, be at leastpartially physically isolated using, for example, protrusions 272.Alternatively, no protrusions 272 are used, and the regions correspondto segments 268 of the showerhead 214.

In operation 704, a plasma pre-treatment is optionally performed. Plasmacan be applied to one or more regions 402 (or to the entire substrate246) prior to deposition processes. For example, the plasmapre-treatment can be used to remove oxidation or other contaminationthat may have formed on a substrate, or can be used to change othercharacteristics, such as the wettability of the substrate. The plasmapre-treatment can also be used to improve the nucleation of ALD or CVDprecursors. The plasma pre-treatment can be applied to one or moreregions 402 and not to others by using different plasma gasses indifferent regions 402, by applying ex-situ plasma differentially, or byusing the alternative showerhead 214 shown in FIG. 5.

In operation 706, a first precursor is provided to at least one of theregions of the substrate (e.g., to the region 402 a). The firstprecursor may be a precursor selected to deposit a material, for exampleTDMAHf to deposit a hafnium based layer. In operation 708, a secondprecursor is optionally provided to at least one of the regions otherthan those to which the first precursor is provided (e.g., to the region402 b). The second precursor may be selected to deposit another materialdifferent from the material formed by the first precursor, for example,TDEAT or TDMAT to deposit a titanium containing layer.

In some embodiments, the combinatorial variation is with respect to theprovision of plasma to the regions. For example, the same precursor maybe provided to all the regions of the substrate, while a plasma isstruck in a first region and not in a second region. Alternatively, oneregion of the substrate may have one precursor provided to it, whileanother region of the substrate has another precursor provided to it. Inthis way, a first material and a second material different from thefirst material are both formed on the substrate.

In operation 710, a plasma is provided to the first region and not thesecond region or to both the first region and the second region. In oneembodiment, if the plasma is provided to both the first region and thesecond region, different precursors are provided to the first and secondregions, respectively, so that a first material different from a secondmaterial is formed in the first and second regions of the substrate,respectively. In another embodiment, parameters of the plasma can bevaried across regions where a plasma is struck in more than one region.Parameters or conditions of PECVD and PEALD that can be varied forcombinatorial processing include power to ignite plasma, flow of plasmaand other gasses, the type of plasma gas, pressure, selection ofprecursors, exposure time, etc. In some embodiments, different plasmagasses are provided to different regions so that some of the plasmagasses may ignite and others may not. In further embodiments, thedistance between some segments 268 of the showerhead 214 to the pedestal218 may vary (see FIG. 5). The distance between a segment 268 and thepedestal 218 can therefore also be a combinatorial variable. Operations706-710 are repeated as necessary to generate the number of desiredcycles for ALD to test gestation periods or to create the desiredthickness of the layers.

In operation 712, the materials deposited on the substrate arecharacterized. Characterization can include any one of severaltechniques to measure physical and other properties of the depositedmaterials. For example, characterization may include measuring thickness(e.g., ellipsometry), density, phase, resistance, leakage, breakdownvoltage, capacitance (i.e., dielectric constant), contact angle, andother properties using probes and other instruments. Characterizationcan also include imaging techniques such as scanning electron microscopy(SEM), tunneling electron microscopy (TEM), atomic force microscopy(AFM) and other techniques. Imaging techniques can be used to determinesome properties of films, for example film composition and morphology.Other characterization techniques, including x-ray diffraction (XRD) todetermine film phase and x-ray fluorescence (XRF) composition can alsobe used.

In operation 714, after characterization is complete, the materials areevaluated for further processing, such as is described regarding FIG.1B. As described above, none, one, or both of the materials can beselected for further combinatorial processing (e.g., secondary ortertiary stage processing) or manufacturing.

V. Plasma Enhanced Deposition Examples

A. Plasma Enhanced ALD

FIGS. 8-11 are timing diagrams for performing combinatorial plasmaenhanced ALD processing. The timing diagrams describe several scenariosfor forming multiple materials on a substrate using combinatorial PEALD.FIG. 8 shows a scenario where two different precursors are appliedsequentially and plasma is applied across the substrate. FIG. 9 shows ascenario where two different precursors are applied simultaneously andplasma is applied across the substrate. FIG. 10 shows a scenario where asingle precursor is used across the substrate and the plasma is variedbetween regions of the substrate. FIG. 11 shows a scenario where twodifferent precursors are provided and plasma is varied across regions ofthe substrate. Other variations are possible and these examples aremerely representative of the possible types of experimentation and notmeant to be limiting in the possible applications of this invention. Thecycles shown in FIGS. 8-11 can be repeated to deposit multiple layers.

1. Varying Precursors and Using a Common Plasma

As shown in FIG. 8, the flow into four segments of a showerhead areexplained using the flow diagram 800. The flow through the four segments268 a, 268 b, 268 c, and 268 d of the showerhead 214 is shown in theflow diagram 800. As described above, each segment 268 may correspond toa region 402 of a substrate 246 to deposit a material 302 thereon. Thetotal flow through the showerhead 214 is approximately constant. Forexample, as shown here, the total flow through the showerhead is alwaysapproximately 1000 sccm (250 sccm for each segment), although anyappropriate flow may be used. Additionally, although the flow is equalfor each segment 268, in embodiments where segments 268 have differentsizes or different configurations, different amounts of flow may be usedfor each segment 268.

The flow diagram 800 shows the flow of plasma gas 810, purge gas (e.g.,nitrogen gas) 812, a first precursor A 816, and a second precursor B814. The plasma gas can be selected according to Paschen's law (above)so that a plasma is ignited when desired. The RF power 818 is used toignite the plasma. The precursor B 814 and precursor A 816 are typicallysmall amounts of precursor chemical in a carrier gas. For example, theprecursor chemical may be flowed at 1 sccm equivalent, while Argoncarrier gas is flowed at 249 sccm.

The timing diagram is divided into several varying periods of time820-838. During each period of time 820-838, a total of approximately1000 sccm is flowed over the substrate 246. The 1000 sccm can compriseany combination of plasma gas 810, purge gas 812, precursor B andcarrier gas 814 and precursor A and carrier gas 816. In this example,each segment 268 and region 402 receives approximately 250 sccm of flow.When the precursor is delivered to a region 402, each other region 402is exposed to purge gas. So, at time 820, 250 sccm of precursor A andcarrier gas is provided using segment 268 a, while 750 sccm of purge gasis provided using segments 268 b, 268 c, and 268 d.

Generally, as described above ALD can be considered a self-limitingprocess that uses two reagents. In this description, the first reagentis a precursor (e.g., precursor A or B, such as a hafnium precursor oraluminum precursor) and the second reagent is a reactant such as watervapor, ozone, or plasma (e.g., oxygen plasma). A typical ALD cycle mayinclude flowing the precursor, purging to remove excess precursor,reacting the second reagent with the precursor to deposit a monolayer,and a subsequent purging to remove excess reagent. Additional monolayerscan be deposited by repeating the cycle. In some embodiments, asubmonolayer or more than a monolayer are deposited in a cycle.

As shown here, the precursor A is provided using segment 268 a andsegment 268 b at times 820 and 824, respectively. Times 820 and 828 arelonger than times 824 and 832, therefore more of precursor A andprecursor B is provided during times 820 and 828 than during times 824and 832. The length of time that the precursor is flowed over thesubstrate can be a combinatorial variable used to determine, forexample, the amount of time needed to form a saturated adsorbed layer onthe substrate. Times 820-834 describe the first half of the ALD cycle(providing the precursor and purging) for each of the segments 268.

The second half of the ALD cycle is completed by igniting a plasma attime 836. The plasma is struck by providing a voltage difference betweenthe pedestal 218 and the showerhead 214. In this embodiment, a commonplasma gas is flowed across all regions of the substrate, and plasma isstruck in all regions. The ALD deposition process is completed at time838 when the remaining gasses are purged. The cycle can be repeated todeposit multiple layers.

After forming the four different materials 302 in the four regions 402,each of the different materials 302 can be characterized (e.g., usingelectrical testing and/or imaging) and evaluated for subsequentprocessing.

FIG. 9 is a timing diagram 900 describing an ALD cycle in which twodifferent precursors are delivered to two different regions of asubstrate simultaneously. As with the timing diagram 800, the timingdiagram 900 shows the flow to segments 268 a-d. The flow of a firstprecursor A and carrier gas 910, the flow of a second precursor B andcarrier gas 912, the flow of purge gas 914, the flow of plasma gas 916,and the amount of RF power 918 are shown in line graphs. The gas flowedinto each of the segments 268 a-d and the amount of flow or power910-918 is shown for times 920-930.

As can be seen in the timing diagram 900, at time 920, precursor A andcarrier gas is flowed through segment 268 a and precursor B and carriergas is flowed through segment 268 c, while segments 268 b and 268 d flowpurge gas. At time 922, the entire substrate 246 is purged to removeexcess precursor. At time 924, precursor A and carrier gas is flowedthrough segment 268 b and precursor B and carrier gas is flowed throughsegment 268 d, while segments 268 a and 268 c flow purge gas. Again, attime 926, the entire substrate 246 is purged to remove excess precursor.Times 920-926 are the first half of an ALD cycle. Time 920 is longerthan time 924, and this exposure time is a parameter than can be variedcombinatorially.

At time 928, plasma gas is flowed through all segments 268 a-d, and aplasma is struck by creating a voltage difference by applying RF power918 between the showerhead 214 and the pedestal 218. Striking the plasmacompletes the ALD cycle and a monolayer is formed in each of the regionsof the substrate 246. The substrate 246 is purged again at time 930. Insome embodiments, the layer deposited may be a submonolayer or greaterthan a monolayer. The cycle can be repeated to deposit multiple layers.

2. Varying Plasma Across Regions

FIG. 10 is a timing diagram 1000 for varying plasma across regions whenperforming combinatorial PEALD. Segments 268 a-d correspond to regions402 a-d on the substrate 246 that are combinatorially processed. Thisexample uses a single precursor and multiple plasma gasses and exposuretimes to evaluate the effects of those parameters on depositingmaterials.

A graph 1010 shows the flow of precursor plus carrier gas. A graph 1012shows the flow of purge gas. A graph 1014 shows the flow of a firstplasma gas 1 and a graph 1016 show the flow of a second plasma gas 2.The graph 1018 shows the amount of RF power being used.

In this example, each of segments 268 a-d receives 250 sccm of precursorA plus carrier gas at time 1020. As shown in graph 1010, precursor Aplus carrier gas is flowed at 1000 sccm (i.e., 250 sccm for each ofsegments 268 a-d). At time 1022, purge gas is flowed across thesubstrate to remove excess precursor. Times 1020 and 1022 describe thefirst half of an ALD cycle. Times 1024-1038 describe the second half ofthe ALD cycle.

The ALD cycle used here combinatorially varies plasma gas and theexposure time. For example, segments 268 a and 268 b flow plasma gas 1at times 1024 and 1028, respectively. Time 1024 is longer than time1028, and more power (i.e., 750 W vs. 500 W) is used to strike theplasma during time 1024. In some embodiments, plasma gas 1 may be chosensuch that conditions are not sufficient to strike a plasma in segment268 b (e.g., not enough power or too much distance/separation).Optionally, another second reagent can be used to complete the formationof the ALD layer.

Regions corresponding to segments 268 c and 268 d are exposed to plasmagas 2 at times 1032 and 1036, respectively. Time 1032 is longer thantime 1036 and more power (i.e., 750 W vs. 500 W) is used to strike theplasma at time 1032 than at time 1036.

In these embodiments, the effects of two different plasma gasses,different power levels, and different exposure times can be evaluated sothat an optimum solution can be derived. The deposited layer may, invarious embodiments, be a monolayer, submonolayer, or greater than amonolayer.

FIG. 11 is a timing diagram 1100 describing an embodiment where twodifferent precursors are delivered simultaneously and two differentplasma gasses are delivered simultaneously. As with the other timingdiagrams, timing diagram 1100 shows the delivery of gasses throughsegments 268 a-d at times 1122-1132. The power or flow of each gas orpower source is shown in graphs 1110-1120.

At time 1122, a first precursor A is delivered to segment 268 a and asecond precursor B is delivered to segment 268 c. At time 1124, thesubstrate 246 is purged to remove excess precursor. At time 1126,precursor A is delivered to segment 268 b and precursor B is deliveredthrough segment 268 d. At time 1128, the substrate 246 is again purgedto remove excess precursor. Time 1122 is longer than time 1126,therefore the exposure time of the precursors to the substrate is variedcombinatorially. Times 1122-1128 are the first half of an ALD cycle.

Times 1130 and 1132 are the second half of the ALD cycle. The secondreagent is again the plasma, which is delivered at time 1130. Two plasmagasses are simultaneously delivered to the substrate: plasma gas 1 tosegments 268 a and 268 b, and plasma gas 2 to segments 268 c and 268 d.Full RF power 1120 is provided at time 1130 to ignite the plasmathroughout the substrate. In some embodiments, the plasma gas 1 may be agas that is easy to ignite (e.g., Ar), while plasma gas 2 is a gas thatis difficult to ignite (e.g., H₂), so that plasma is provided in theregions corresponding to the segments 268 a and 268 b and not in theregions corresponding to segments 268 c and 268 d. The deposited layermay, in various embodiments, be a monolayer, submonolayer, or greaterthan a monolayer.

3. Other Examples

The four timing diagrams 800, 900, 1000, and 1100 are examples ofcombinatorially varied PEALD. Various other processes can be developedand used according to embodiments of the invention. For example, in someembodiments, plasma can be used in the ALD cycle to deposit a materialin one or more regions of a substrate, while another reagent (e.g.,water vapor) is used to form an ALD deposited material in other regions.In this way, the differences between conventional ALD and PEALD can beexplored using a single experiment. Also according to other embodiments,more than two different precursors could be used, and other variablescould be explored.

B. Plasma Enhanced CVD

PECVD uses plasma as an enhancement to improve reaction rates and toreduce processing temperatures. Plasma can also be used with CVD to varythe film properties, e.g., density, composition, step coverage,adhesion, dielectric constant, film leakage, breakdown voltage, etc.Various different scenarios can be used to perform combinatorialprocessing using PECVD. As with combinatorial PEALD, precursors can bevaried across regions while plasma is applied to all regions of thesubstrate. According to another example, plasma can be provided in oneor more regions, while not provided in others. In this second example,the same precursor can be provided to all regions, or the precursor orother parameters of the PECVD can be varied.

Unlike ALD, CVD is not self-limiting, and CVD films continue to grow thelonger a substrate is exposed to the CVD precursors and plasma. For someCVD processes, one or more precursors and a plasma can be providedsimultaneously for a desired amount of time to grow a layer of a desiredthickness. As a result, for combinatorial PECVD, several parameters forCVD can be varied to determine an optimum solution such as precursorexposure time, precursor mixture, plasma gas composition and voltages.

For example, two regions can be exposed to the same precursor fordifferent amounts of time to study the growth rate of the precursors.Alternatively, two regions could be exposed to the same precursor, oneregion with plasma and the other without for the same amount of time tostudy the change in growth rate when using plasma. As with PEALD,different plasma gasses, different distances between the pedestal 218and the showerhead 214 (see FIG. 5), and other plasma variable can becompared for PECVD to determine an optimum plasma solution. The otherembodiments described above, e.g., rotating the pedestal 218, can alsobe used for combinatorial PECVD.

In one embodiment, a material deposition system is described. Thematerial deposition system includes a pedestal, and a showerheaddisposed opposite the pedestal. The showerhead includes multiplesegments to simultaneously flow different fluids, a first segment of theshowerhead is configured to provide a first precursor and a plasmabetween the pedestal and the showerhead to deposit a first material, anda second segment of the showerhead is configured to deposit a secondmaterial different from the first material.

In another embodiment, the showerhead and the pedestal are conductiveand the plasma is provided by generating a power through a first gasemitted by the showerhead and between the showerhead and the pedestal.

In another embodiment, a first distance between the first segment andthe pedestal is sufficient to cause a breakdown voltage and ignite theplasma under the first segment when the power is generated while noplasma is generated in the second region.

In another embodiment, the showerhead includes multiple protrusionsbetween the multiple segments to designate multiple regions.

In another embodiment, the material deposition system includes a bodyinside a plenum of the showerhead to direct the first precursor towardthe first region.

In another embodiment, the plasma is generated externally from theshowerhead and provided to the substrate through the showerhead.

In another embodiment, a second gas different from the first gas isemitted by the second segment, and the plasma is not ignited in thesecond gas.

In another embodiment, material deposition system is one of a chemicalvapor deposition (CVD) system, an atomic layer deposition (ALD) system,a plasma enhanced CVD (PECVD) system and a plasma enhanced ALD (PEALD)system.

In another embodiment, the pedestal is grounded and the showerhead isattached to an RF power supply.

In another embodiment, the showerhead is grounded and the pedestal isattached to an RF power supply.

In one embodiment, a method is described, including designating multipleregions of a substrate, providing a global flow of fluids to themultiple regions of the substrate including providing a first precursorto at least a first region of the multiple regions, and providing aplasma to the multiple regions to deposit a first material on the firstregion formed using the first precursor. In this embodiment, the firstmaterial is different from a second material formed on a second regionof the substrate.

In another embodiment, providing a global flow includes providingapproximately equal fluid flow to each of the multiple regions.

In one embodiment, a method is described, including designating multipleregions on a substrate, applying a first plasma to a first region of themultiple regions and not to a second region of the multiple regions, andproviding a first precursor to the first region to deposit a firstmaterial in the first region.

In another embodiment, the method further includes providing the firstprecursor to the second region to deposit the first material in thesecond region.

In another embodiment, the method further includes providing a secondprecursor to the second region to deposit a second material in thesecond region.

In another embodiment, the method further includes providing a secondplasma in the first region to deposit the first material.

In another embodiment, the method further includes providing the secondplasma in the second region to deposit the second material.

In another embodiment, the method further includes providing no plasmain the second region to deposit the second material.

Although the foregoing examples have been described in some detail forpurposes of clarity of understanding, the invention is not limited tothe details provided. There are many alternative ways of implementingthe invention. The disclosed examples are illustrative and notrestrictive.

1. A method, comprising: designating a plurality of regions on a surfaceof a substrate; providing a showerhead, wherein the showerhead comprisesa plurality of segments; depositing a first material on a first regionof the surface of the substrate, wherein the depositing of the firstmaterial comprises; providing a first precursor to the first region ofthe surface of the substrate; providing a first plasma to a firstsegment of the showerhead, providing the first plasma to the firstregion of the surface of the substrate; and depositing a second materialon a second region of the surface of the substrate.
 2. The method ofclaim 1, further comprising: providing the first plasma in the firstregion of the surface of the substrate without providing the firstplasma in the second region of the surface of the substrate.
 3. Themethod of claim 1, wherein providing the first plasma comprises:providing a first gas to the first region of the surface of thesubstrate; generating a voltage difference between a showerhead segmentproviding the first gas and a pedestal holding the substrate equal to orgreater than a breakdown voltage of the first gas to ignite the firstplasma above the first region of the surface of the substrate.
 4. Themethod of claim 1, wherein providing the first plasma comprisesproviding the first plasma from a remote plasma source, and wherein theremote plasma source is one of a radio frequency source, a microwavesource, or an electron cyclotron resonance source.
 5. The method ofclaim 1, wherein providing the first precursor and providing the firstplasma are performed sequentially.
 6. The method of claim 1, whereinproviding the first precursor and providing the first plasma areperformed approximately simultaneously.
 7. The method of claim 1,further comprising providing a second gas to the second region of thesurface of the substrate.
 8. The method of claim 7 further comprising:wherein the first gas and the second gas are emitted from a firstsegment and a second segment of the showerhead; wherein the substrate isdisposed on a pedestal opposite the showerhead; and generating a voltagedifference between the pedestal and the showerhead to provide the firstplasma above the first region of the surface of the substrate and to notprovide the first plasma above the second region of the surface of thesubstrate.
 9. The method of claim 8, wherein a distance between thepedestal and the showerhead, and the first gas is sufficient to providethe first plasma above the first region of the surface of the substrate,and the distance between the pedestal and the showerhead, and the secondgas to not sufficient to provide the first plasma above the secondregion of the surface of the substrate.
 10. The method of claim 1,further comprising moving the first plasma from above the first regionof the surface of the substrate to above the second region of thesurface of the substrate.
 11. The method of claim 10, wherein moving thefirst plasma comprises changing a first gas mixture above the firstregion of the surface of the substrate and changing a second gas mixtureabove the second region of the surface of the substrate to extinguishthe first plasma above the first region of the surface of the substrateand to ignite the first plasma above the second region of the surface ofthe substrate.
 12. The method of claim 1, further comprising providing asecond precursor different from the first precursor to the second regionof the surface of the substrate.
 13. The method of claim 1, furthercomprising providing the first precursor to the second region of thesurface of the substrate.
 14. The method of claim 1, wherein each of themultiple regions of the surface of the substrate have approximately asame size and approximately a same shape.
 15. The method of claim 1,wherein a total flow to each region of the surface of the substrate ofthe plurality of regions of the surface of the substrate isapproximately equal.
 16. The method of claim 15, wherein the total flowis axisymmetric over the substrate.
 17. The method of claim 1, whereinthe materials are deposited using one of chemical vapor deposition (CVD)or atomic layer deposition (ALD).
 18. The method of claim 3, furthercomprising: providing the first gas to the second region of the surfaceof the substrate; generating the voltage difference between the pedestaland the showerhead; wherein a first distance between a first segment ofthe showerhead corresponding to the first region of the surface of thesubstrate and the substrate is sufficient to cause the breakdown voltageand ignite the first plasma above the first region of the surface of thesubstrate; and wherein a second distance between a second segment of theshowerhead corresponding to the second region of the surface of thesubstrate and the substrate is insufficient to cause the breakdownvoltage and ignite the first plasma above the second region of thesurface of the substrate.
 19. The method of claim 1, further comprisingproviding a second plasma different from the first plasma above thesecond region of the surface of the substrate.
 20. The method of claim17, wherein providing the second plasma occurs sequentially withproviding the first plasma.